1. Field of the Invention
This invention relates generally to devices useful in endoscopic diagnostic and surgical procedures, and more specifically to barrier-forming or shielding means insertable into a cavity within the body through a small incision or other aperture, and methods of using the same.
2. Brief Description of the Prior Art
The endoscope is a narrow tubular device having optical transmission capabilities which is inserted through a small incision or other aperture into a cavity within the body to facilitate inspection of the interior of the cavity. Endoscopic diagnosis and surgery are performed by using an endoscope in conjunction with other instruments which are designed to perform typical diagnostic or surgical functions, but which have been adapted for insertion through other nearby apertures. These devices typically comprise a long narrow tube, with an operative mechanism, such as scissors, forceps, or a clamp, situated at the distal end of the tube and connected by some connecting means disposed within the tube to a manual actuation means situated at the proximal end. Use of these devices has the advantage of lessening the trauma which is necessarily experienced by a patient in the course of a surgical procedure, thereby reducing risk, pain, recovery time, and costs.
Within the field of endoscopic diagnosis and surgery, there has been a long-felt need for a barrier-forming device which is insertable through a small incision or other aperture but which can be subsequently expanded to occupy a much greater planar area. Such a device has applications in retraction of tissues to prevent them from obstructing the work of other instruments, in providing shielding for sensitive tissues and organs from the damaging effects of laser surgery or radiation therapy, or in providing a grasping means useful for engaging and holding an organ such as the uterus by walls of its lumen, without engaging or otherwise disturbing the tissue on the outside of the organ. While there are several patents disclosing devices which address these needs, to date they remain either unfulfilled or only partially fulfilled by the existing prior art.
U.S. Pat. No. 5,178,133, issued Jan. 12, 1993 to Pena, discloses a laparoscopic retractor device having two rigid arms supporting a membrane which are disposed within a tube and are activated by a plunger. In this device the arms unfold in opposing directions through pivotal rotation at the end of the tube. A membrane, consisting of a tubular latex sheath having an open and a closed end, is disposed about the arms while they are in their folded position, and is expanded by the arms when they are spread apart. The device requires a biasing force to expand the arms and retain their position relative to one another against the elastic force of the membrane.
U.S. Pat. No. 5,176,128, issued Jan. 5, 1993 to Andrese, teaches an organ retractor comprising a pair of flexible arms formed in their operative extended shapes which are deformed and disposed within an introducer having an oblong cross section and containing separate apertures for each arm and a plunger mechanism. Upon expulsion from the introducer, the arms radiate in opposing directions, and filaments disposed between the arms and affixed to the plunger mechanism provide some reinforcement for maintaining their proper orientation. The device cannot provide a solid barrier for purposes of either retraction or shielding.
U.S. Pat. No. 5,074,867, issued Dec. 24, 1991 to Wilk, teaches a membrane disposed within a tube which is ejected upon insertion of the tube into a body cavity and partially expanded by elongate members. The membrane must subsequently be fully expanded and oriented about the area to be shielded through the use of laparoscopic forceps.
U.S. Pat. No. 4,559,944, issued Dec. 24, 1985 to Jaeger, teaches surgical forceps having two arms of unequal length, wherein the longer of the two arms is insertable through the cervix into the uterus, while the shorter arm is shaped to grip the outside of the cervix by capturing it between the arms. The longer arm is further provided with a longitudinal bore, and is tipped with an inflatable membrane which, when inflated, engages the walls of the lumen of the uterus, thereby providing a measure of control of the positioning of the uterus. The device cannot accomplish gripping or manipulation of the uterus or cervix without engagement of the outer surface of the cervix.